Killed a big whitetail doe with my XP-100 .221 Fahrball one time. Did it on a cull property .....just to see. A single 52 gr Hornady BTHPM through the slats at about 80 yards and she expired without a fight. So, I reckon the .223 would do all of that and mo' better, yet...... especially with a more suitable projectile.
That being said, I likely will never prove the theory as there is one or two better suited rifles laying around if deer need shooting.
